Red Rubber Stoppers One Hole 21mm - Pack of 10

Best quality Red Rubber. Shore hardness in range 46-55. Bottom diameter moulded on top face.

Holes 5mm diameter.

• Bottom diameter: 21mm

• Top diameter: 24.5mm

• Length: 28mm

• Pack of 10

Please note: Extreme care must be used when inserting glass into the holes in rubber stoppers. The procedure should only be carried out by trained personnel. If in doubt consult your safety advisor.

Size 21 stoppers are ideal to use with Pyrex HD NM Conical Flasks 125mL and Simax NM flasks 50-100mL.